The design of playground equipment complexes has been confined to conventional sketches or architectural drawings. Rearrangement and experiment therefor involve time consuming redrawing. In other areas of design, more flexibility was obtained by the use of interchangeable scale models. Such models have been used in the design and planning of layouts for offices, manufacturing plants and homes. But the scale models used were either bulky outlines made of magnetic materials which adhered only to metal plates, or were constructed of opaque materials and placed on opaque backgrounds. Further, all such prior design systems were limited to placing the models on grid like interior floor plans. Opaque models on opaque backgrounds made photocopying or overhead projection virtually impossible. Finally, no design system adaptable to outdoor areas has been disclosed.